'New silk road'
Mirek Topolanek, the Czech prime minister, said the aim to open up a "southern corridor" for supplies was "not just a one-way street for pipelines."
He said: "We envisage this as a new silk road where we'll see the flow of information, goods, people and energy in both ways."
Representatives from the United States, Russia and Ukraine also attended the summit as observers to the agreement.
Iraq, which was also invited to the meeting, did not send any officials.
The summit was called to help kick-start the Nabucco pipeline, which would link the EU to gas rich nations on and beyond the Caspian Sea, bypassing Russia and Ukraine.
The pipeline, which once completed would stretch 3,300km from Turkey to Austria, could transport up to 31bn cubic metres of gas each year to western Europe.
It is hoped that it will start pumping gas to Europe by 2014.
The EU is keen to speed up the construction of the pipeline after a dispute between Russia and Ukraine in January over gas prices left large areas of Europe without supplies of the resource for two weeks.